Process of producing hollow sheet-metal articles



, PAT-EDITED DEC. 10, 1907. R. GHILLINGWORTH. mm

PROCESS OF PRO NG HOLLOW SHEET METAL ARTICLES.

' APPLICATION FILED AUG. 15, 1900.

PATENTED DEC. 10, 1907.

GHILLINGWORTH.

Paqcbss 01?Paobucme HOL'LOYWYSHEBT METAL ARTICLES;

mmnugrs RUDOLF CHILLINGWORTH, or NUREMBERG, GERMANY.

PROCESS OF PRODUCING HOLLOW SHEET-METAL ARTICLES To alljehom it mai cancer/rt: Be it known that I, RUDoLF OHILLING- fwon'rn, a subject of the German Emperor,

residing at Nuremberg, Kingdom of Bavaria, Germany, have mvented Improvements in Processes for ProducingQHollow Sheet-Metal Articles, of which the following is a description.

This invention relates. to an improved method or process of producing shell or troughshaped cases or -articles of sheet metal and consists in first bending a sheet of metal withoutdrawing or stretching the same, and

, thereafter subjecting the sheet to a drawing or stretching action until it is brought into the shape of the desired article The apparatus for carrying out the inven tion consists of a matrix which is open on two opposite sides and the cross section of which is formed like the bottom of the case to be produced; it consists further of a matrix or die shaped correspondingly and composed of two arts. The matrix has, at least the same wirth asthat of the sheet to be used for producing the case, and thesurfacclines standing perpendicularly with respect to the middle plane of the matrix are rectilinear. In the matrix is also provided a recess having the same shape, width and depth as the metal article to be-produced. The parts forming the die are arranged adjustably within each other, however they may also firmlybe connected with each other. The inner adjustable part has the size of the hollow space of the case to be produced and fits into the cavity of the matrix. Such an apparatus is shown inthe accompanying drawings, in which,

Figure I is a sectional elevation. Fig. II is a transverse section, showing the parts in the position assumed at the beginning of the operation. Figs. III and IV are views similar to Figs. I and II respectively showing the parts in position assumed at the completion of the preliminary bending. Figs. V and VI are similar views respectively showing the position of the parts assumed after the completion of the article. Fig. VII an elevation of a, modification. Fi VIII a plan view of the same, and Fig. Iii a trans verse section.

Thedie consists of two parts 6 and a. connected with each other by means of a bolt on or the like. Said parts are placed perpendicularly above the matrix I7 and form j ointl with their lower surfaces the matrix which Specification of Letters Patent. Application filed August 15. 1900. Serial No- ZGXQOQ, I

.paratory pressing of the sheet, as a drawe;

ture, they are bent upwardly and constitute Patented nee. 1o, 907.

serves for ther'eparatory pressing of sheet 6 (Figs. I and II). Sheet 6 placed on'the er edge of the matrix, .is pressed by e 0, when the latter descends mto the matrixand is there shaped like the latter (Fig s. III 1 and IV). As can be seen, especially from Figs. I and. II the? matrix has in its center a downward" projecting recess f which serves after the preopening and into which fits, accurately, ;cen tral part b of the die which art must be separated from die 0 after bo t a has been removed. Therefore, the outer die cylleinains in its position, while the central part ,1), which acts now as a draw-die, is moved; further downward and draws sheet e out in the form of a shell corresponding to the sha e-ofthe die and of the draw-opening (Figs: and VI).

The apparatus represented in Figs'VII to; IX conslsts of the two parts 6 andc forming the die, said parts being connected with each other by means of bolt a. The matrix at con i sists of two molds which are reinforced by ribs and screwed together and which inelose f between each other the draw-0pening Said matrix shows, like the outer part c of the die and like the metal sheet which has to be transformed, an oval outline so that when the sheetn'ietal is, at first, made to undergo a preparatory pressure and then drawn, a shell is obtained the up er edge of which hes about horizontally. T ie outer part a of the die is further provided with guide-ribs g for the draw-die and carries on its circumference several projecting nosepieces into the recesses of which engage the guide-bolts provided on the circumference of matrix (1.

The mode of producing cases by means of the new process is the following: In the first lace, the metal sheet is subjected 1n the liollow mold or matrix to a preparatory bending only in such a manner that it is bent only in the vertical plane so that the surfacelines standing perpendicular with regard to a transverse lane are straight or rectilinear.

"Thereupon t ie'middle piece, which retains.

its form unchanged, is pressed down; a second working operation, and after bolt (1; has been removed into the recess of the matrix by means of the adjustable part b ofthe die; those arts adjoining the middle-piece laterally being hereby pressed into the aperthen the parallel sides of the metal case.

. The present process has important advantages over those to me. When this process is used it 1s posslble to avoid the occurrence of cracks in the sheet metal during the pressing and drawing. The Worked piece being pressed, at

"first, only in a, vertical plane, it is thereby -i not subjected to any strain which might cause cracks.

Considering, further, that the piece prepared during the first working 0 eration is bent up, during the drawing, so ely around the edges of the draw-die, this operation also does not present any danger of the sheet being tom.

* ftrough shaped articles of claim as my invention: The herelndescribed method of forming sheet metal which processes heretofore known 1 consists in first bending the entire sheet of metal into the curved form of the curved part of the finished article so that all surface ines perpendicular to a transverse plane are straight or rectilinear, sustaining, a portion of said curved part of the finished article, and simultaneouslydrawing the remainder of the blank so that all surface lines are arallel to each other and to the transverse p ane, substantially as described.

In witness whereof I have hereunto set my hand in presence of two witnesses.

RUDOLF CHILLINGWORTH Witnesses Gnome SCHMIDT, CONRAD WonNnR. 

